Can we run our cars on human fat?

A Beverly Hills cosmetic surgeon attracted attention from alternative energy buffs and public health officials after he announced that he was using liposuctioned fat to fuel two SUVs.

A Beverly Hills cosmetic surgeon attracted attention from alternative energy buffs and public health officials after he announced that he was using liposuctioned fat to fuel two SUVs.

Dr. Craig Alan Bittner, owner of the Beverly Hills Liposculpture clinic, claims that he produced biodiesel from the excess lipids hoovered from his patients' backsides, which he then put into the tanks of his Ford Explorer and his girlfriend's Lincoln Navigator.

Forbes quotes from Dr. Bittner's now-defunct website:

"The vast majority of my patients request that I use their fat for fuel – and I have more fat than I can use," Bittner wrote on lipodiesel.com. "Not only do they get to lose their love handles or chubby belly but they get to take part in saving the Earth."

As the Telegraph reports, Bittner's flab-to-fuel scheme raised eyebrows at the California Department of Public Health, who noted that there are laws covering what one can and cannot do with medical waste. The agency says it has opened an inquiry.

In the meantime, Bittner has apparently hared off to South America. On the Beverly Hills Liposculpture website, the doctor, who says that he first started practicing medicine in a rural clinic in Colombia, says he has returned to the continent (he didn't say which country) "to volunteer with a small clinic that is very similar to where my medical career began decades ago, where I can help those most in need."

Did Bittner really run his cars on "lipodiesel"? Fat chance, says Wired, noting that only cars with diesel engines can accommodate biodiesel, and that there is currently no such thing as a diesel-powered Lincoln Navigator. "No diesel, no lipodiesel — just a Lincoln with high cholesterol," writes Keith Barry.

Sure, they could have swapped out the engine, but Wired also notes that Bittner's previous venture was shut down after authorities claimed he was engaging in false advertising, and that Bittner is certified as a radiologist, not a cosmetic surgeon. Mr. Barry writes:"We truly hope his lipodiesel experiment was just another flabrication."

That said, it is in fact possible to produce biodiesel from human fat. Just like that of animals, our own lard contains trigylicerides, which can be turned into combustible fuel through a process known as transesterification.

It's been done before. The Earthrace, a high-speed eco-boat that broke records last year when it circumnavigated the globe in just under 61 days, was powered partly by former love-handles. According to National Geographic, Captain Peter Bethune and two volunteers donated a combined 2.5 gallons of fat, enough to power the boat for 9 miles.

A symbolic gesture to be sure, but can it be scaled up? After all, if paunch were petroleum, the US would be Saudi Arabia. According to statistics compiled by the Endocrine Society and the Hormone Foundation, about 127 million adults in the US are overweight. Of these, 60 million are considered obese, and 9 million of those are considered extremely obese.  Are we literally sitting on the answer to energy independence?

Sadly, no. The United States consumes almost 21 million barrels of oil each day, which works out to 882 million gallons of gasoline. (Although as the science new site PhysOrg pointed out earlier this month, 3 million of those gallons are burned each day by hauling around our excess fat.) So if we were to replace all of our gasoline with human-fat-derived biodiesel,  every overweight American would have to kick in almost seven gallons of blubber every single day.

In short, even the American kiester isn't wide enough to meet the nation's fuel needs. If you want to burn fat for transportation, get a bike.